X-ray CT Helical Shuttle Scan Position Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The helical shuttle scan in X-ray CT apparatuses often experiences positional displacement and timing differences due to cradle characteristics or subject weight variations, leading to decreased image quality and unnecessary exposure.
Innovation Solution
An X-ray CT apparatus with a scan controller that prioritizes scan position and time settings to maintain consistent helical shuttle scan parameters, incorporating waiting times and stationary scans to ensure accurate data acquisition and minimize exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If helical shuttle scan is performed with reciprocating motion in z direction, then imaging coverage is improved, but positional displacement and timing difference occur due to cradle characteristics or subject weight variations
Solution Approach 1:
The scan controller receives actual position information from the cradle and compares it with the planned position. When positional displacement is detected, the controller automatically adjusts the scan timing and position parameters to correct the deviation, ensuring accurate data acquisition despite cradle characteristics or subject weight variations.
Solution Approach 2:
The system performs preliminary positioning adjustments before the actual scan begins. The scan controller pre-calculates compensation values based on expected cradle behavior and subject weight variations, adjusting the reciprocating motion parameters in advance to prevent positional displacement during the scan.
2Loss of time
If helical shuttle scan terminates in the middle of predetermined imaging range, then scan time is reduced, but exposure waste occurs
Solution Approach 1:
The scan controller continuously monitors the actual scan progress and compares it with the planned imaging range. When the scan approaches the predetermined range boundary, the controller adjusts the reciprocating motion to ensure complete coverage, preventing premature termination and associated exposure waste while optimizing scan time through real-time position correction.
3Measurement precision
If waiting time is added between reciprocating movements, then positional displacement is reduced, but scan time increases
Solution Approach 1:
Instead of using fixed waiting time, the system dynamically adjusts the pause duration between reciprocating movements based on actual cradle position and scan progress. The scan controller calculates the optimal waiting time needed to achieve positional stability, minimizing unnecessary delays while ensuring accurate data acquisition at critical scan positions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for planned X-ray projection data acquisition, reducing image quality degradation and exposure waste by correcting positional and timing discrepancies during helical shuttle scans.
Implementation Method 1
an X-ray generator for generating X-ray, and an X-ray detector for detecting the X-ray generated by the X-ray generator and transmitted through a subject
Data Source
AI summary
An X-ray CT apparatus enables decreasing the degradation of image quality and reducing futile exposure to X-ray in a helical shuttle scan. The X-ray CT apparatus comprises: a gantry rotating device having an X-ray generator for generating the X-ray and an X-ray detector for detecting the generated X-ray and transmitted through a subject; a gantry controller for performing the helical shuttle scan by reciprocally moving the gantry rotating device and the cradle; a scan condition setting device for setting the scan condition of the helical shuttle scan in a predetermined range in the direction of body axis of the subject; an X-ray projection data acquisition device for acquiring the X-ray projection data; a scan controller for controlling the scan as specified in the scan condition; and a image reconstruction device for performing the image reconstruction processing based on the X-ray projection data.